Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF THE INVENTION
I.V. ALERT SYSTEM
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The present invention relates to the field of alar~ devices
usinq CMOS (Complimentary Metal O~ide Semiconductor) di~ital
circuitry. More sPecifically it is a driP I.V. alarm used to
alert the user that an intravenous infusion therapy has been
comPleted. The invention has Photovoltaic cells to detect each
drop in an I.V. chamber. Each successive droD retriggers a
counter. A lon~ pause after a drop will set off alarm circuitrY
to warn of the comPleted I.V. infusion.
DESCRIPTION OF THE PRIOR ART
The followinq is a discussion of Patents felt to be related
in the field of the Present invention. but do not disclose,
whether sinqly or in combination, the aPplicants' unique
construction.
U.S. Patent No. 4.681.569 issued to StePhen Coble discloses
a batterv-operated rate meter used for monitorin~ the fluid flow
of an intravenous feedin~ sYstem which comprises a housin~ havin~
li~ht emitters Positioned opposite one another about the base of
the drip chamber. The said rate meter calculates the passa~e of
drops usin~ photo-detectin~ properties therein and disPlays the
detected inPut throu~h LED indicator means.
U.S. Patent No. 4,014,010 issued to Walter Jinotti discloses
a device similar to the patent described above in that the
intravenoUs ystem flo~ meter ComDrisinq liqht detector means and
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electronic circuitrY therein is used in combination with an alarm
circuit havinq audio si~naling means to warn the oPerator of
fluid flow drippinq below the set level.
SUMMARY OF THE INVENTION
The present invention is a small. portable I.V. alarm
system. The alarm circuitry consists of CMOS di~ital
electronics. The detector com~rises an infrared photocell
chamber having an emitter side and a receiver sids. The emitter
and receiver are positioned on either side of an I.V. drip
chamber. Drops that Pass through the emitter beam interrupt the
constant volta~e sent by the receiver. A volta~e comparator
sends a si~nal to tri~qer a counter, which counts up to a certain
set delay time. If the counter is not retri~ered bY another
drop at the end of the countin~ sequence. an alarm oscillator is
set in action to operate an alarm buzzer and a visible LED (Ei~ht
Emittin~ Diode). The device can be set in terms of the len~th of
i allowable time delay for the counter and the alarm can be turned
off after an initial si~nal to reset the system as a whole.
Accordin~lY, it is an ob~ject of the present invention to
~rovide a Portable I.V. drip alarm system.
Another obiect of the present invention is to Provide an
I.V. alarm system usinq CMOS circuitry.
It is a further obiect of the present invention to provide
an I.V. alarm system usin~ infrared Photovoltaic cells.
It is still another ob~ect of the present invention to
Drovide an I.V. alarm system with an user-ad~ustable timin~
circuit.
These and other obiects of the present invention will
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readily become aPDarent uPon review of the attached drawings and
sPecification.
BRIEF DES~RIPTION OF THE DRAWINGS
Fig. 1 shows a perspective view of the portable I.V. alarm
system with the driP chamber in outline.
Fig. 2 shows a top view of the I.V. alert system.
Fig. 3 shows a bottom view of the I.V. alert system.
Fig. 4 shows a rear view of the I.V. alert system.
Fig. 5 shows a side view of the I.V. alert system.
Fig. 6 shows a circuit diagram for the I.V. alert system.
Similar reference characters denote corresponding parts
throughout the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Fig. 1 shows the Packaged alarm system 10 having a plastic
casing 11, reset switch 12, alarm sPeaker 37 and an LED indicator
38. The system has two seParate housing or containment sections
1la and 11b that are Placed on either side of an I.V. drip cham-
ber 23. A plurality of arms 13 slide through a bracket 14 having
separate passages 14a for each arm 13, as shown in Fig. 4, allow-
ing the width of the ~aP between the channels 11c,11c on the two
sections 11a, 11b to be ad~iusted in order to accommodate differ-
ent sized driP chambers 23. The whole outer housing assembly 11
can be constructed from a relatively soft, resilient plastic
which would allow arms 13 and brackets 14 to have an easily
slidable friction fit.
Recharger contacts 18 and battery door 17. shown in Figs. 3
and 5. are provided on the side and on the bottom of housing
section 11a. Also included on the housing 11 are 5 or more DIP
(Dual Inline Packaqe) switches 34 that ad~just the alert period
between drops 24 in the drip chamber 23. and an on-off switch 39.
To connect the various components in the two housin~s 11a,11b a
connecting line(not shown) would be sent throu~h or ad~iacent to
the arm 13 and bracket 14 assemblY. The alarm system 10 is small
enough to fit within a normal shirt pocket, bein~ no more than 4
inches by 2 1/8 inches by 7/8 inches thick.
The photovoltaic cell is shown in Fi~s. 1, 2, 3 and 6. The
cell consists of a singular emitter 21 and receiver 22 spaced
opposite each other in the channels 11c of sections 11a and 11b.
The sPecific device used to emit is an infrared diode 21 which
emits a beam of infrared light through a clear I.V. drip chamber
23 to an infrared detector 22. The advanta~e of usin~ infrared
li~ht instead of visible light is that there will be less inter-
ference from the outside visible light sources around the device.
The receiver 22 receives a constant si~nal from the emitter
21 until a droP 24 intercepts the path between emitter 21 and re-
ceiver 22. The interDosing of the drop 24 between the emitter
diode 21 and the receiver 22 changes the receiver's incomin~
si~nal. The receiver 22 is constantly sending out a signal to
the alarm circuitry. This receiver output is chan~ed accordingly
and causes a reaction in the alarm circuitry as will be detailed
below.
The alarm circuitry contains a power source for the whole
device. Nickel-cadmium batteries ~0 of 7.2 volt type are used
because of their long life. These types of batteries are also
easily rechargeable. hence the rechargin~ ports 18 consistin~ of
a common DC port connectable to a conventional batterY recharger
54 which is operable to rechar~e batteries 50 only when on-off
switch 59 is in the off position and the alarm system is not
being used~ as is well known in the battery recharging art.
These batteries 50 should keeP the alarm device functional for
about 5 hours as the device has low power requirements with CMOS
~circuitry.
Fiq. 6 shows the circuit diagram for the device. Sensor
blocl; 31 consists of an emitter and receiver 21.22. A voltaqe
comparator 32 is constantlY checking for voltage fluctuations.
If it detects one, a signal uulse is sent to a counter 33 (4541
type) which begins a countinq sequence. Should another pulse be
sent bY the comparator 32. the counter 33 will be retriggered to
start at the beginnin~. A five-position DIP switch 34, also
shown in Fig. 3, allows the user to set the maximum drop delay
time for the counter 33. Should the counter 33 reach this maxi-
mum delaY count without beinq retriggered bY a comparator Pulse~
the counter 33 outPuts a Pulse to an AF (Audio Frequency~ 1/2
556C tYpe) oscillator 35, which will in turn output a pulse to an
astable modulating oscillator (1~2 556C tYpe) 36. The modulating
oscillator 36 is connected to a Piezo audio transducer or speaker
37 which produces the alarm sound. The two oscillators 35~36 are
capable of producin~ a variety of sounds. A modulated single
tone ~on-off-on-off)~ a modulated dual tone (hi~h-low-high-low)
or an unmodulated sin~le tone. The type of tone can be selected
by the user of the device 10.
A low power visual alarm LED 38 is connectQd to the outPut
of another CMOS timer/multivibrator 52 (555C type) similar to
oscillator 36 which is also controlled by the reset pulse of the
driP sensing comparator 32. Oscillator timings of 100 ms are
good for viewin~. Reset switch 12 would send a pulse back to the
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counter 33 to retri~qer its sequence separately of the voltage
comparator 32.
In use the maximum desired delay time is about 20 seconds.
The five-position DIP switch 34 can select a range between 20
seconds and zero time between droPs in the I.V. chamber 23. The
DIP switch 34 could have a variable amount of positions. Five
are taken as a good sampling of driP times.
It is to be understood that the Present invention is not
limited to the sole embodiment described above, but encompasses
any and all embodiments within the scoPe of the following claims.
